The piano has 7 white notes and 5 black notes.
The rest are all octaves covering all of these same notes.

It's not rocket science...but requires the RIGHT teacher to simplfy the learning process and motivate you - although you should NEVER take up an instrument unless YOU have the motivation to learn. If practising feels like work or is a chore, you've chosen the wrong hobby.

You have ALL the elements of a full symphony orchestra encompassing everything else right down to a solo monophonic note making machine --- at your fingertips. Piano IS the foundation that everything else builds on.

If you're fortunate enough to learn piano first (and preferably at an early age) then it makes learning any other subsequent instrument inherently easier.

To me instruments are like women.
They're all the same and they're all different. :-)